Patients with major depression and healthy control subjects undergo a standard protocol on four occasions. Each time they receive one of: cortisol (hydrocortisone) 7.5 mg, cortisol 20 mg, cortisol 50 mg or placebo. Test substance administration is double blind and in random order; over the four protocols subjects receive each test substance. In the standard protocol blood is drawn through an IV catheter for cortisol and ACTH determinations at regular intervals for 30 min before and 4 h after administration of the test substance.